Cavity-modified unimolecular dissociation reactions via intramolecular vibrational energy redistribution

While the emerging field of vibrational polariton chemistry has the potential to overcome traditional limitations of synthetic chemistry, the underlying mechanism is not yet well understood. Here, we explore how the dynamics of unimolecular dissociation reactions that are rate-limited by intramolecular vibrational energy redistribution processes can be modified inside an infrared cavity. We study a classical model of a bent triatomic molecule, where the two outer atoms are bound by anharmonic Morse potentials to the center atom. We show how energy-dependent anharmonic resonances emerge and that resonantly coupling the optical cavity to particular dynamical resonance traps can either significantly slow down or increase the intramolecular vibrational energy redistribution processes depending on the strength of vibrational momentum-momentum mode coupling, leading to altered unimolecular dissociation reaction rates. These results demonstrate that chemical reactivity can be modified inside a cavity and lay the foundation for further theoretical work toward understanding the intriguing experimental results of vibrational polariton chemistry.

Entangled photons from composite cascade emitters

Entangled photons are crucial for quantum technologies, but generating arbitrary entangled photon states deterministically, efficiently, and with high fidelity remains a challenge. Here, we demonstrate how hybridization and dipole-dipole interactions---potentially simultaneously available in colloidal quantum dots and molecular aggregates---leveraged in conjunction can couple simple, well understood emitters into composite emitters with flexible control over the level structure. We show that cascade decay through carefully designed level structures can result in emission of frequency-entangled photons with Bell states and three-photon GHZ states as example cases. These results pave the way toward rational design of quantum optical emitters of arbitrarily entangled photons.

A Roadmap Toward the Theory of Vibrational Polariton Chemistry

The field of vibrational polariton chemistry was firmly established in 2016 when a chemical reaction rate at room temperature was modified within a resonantly tuned infrared cavity without externally driving the system. Despite intense efforts by scientists around the world to understand why the reaction rate changes, no convincing theoretical explanation exists. In this perspective, we briefly review this seminal experiment, analyze the relevance of leading theories, and construct a roadmap toward the theory of vibrational polariton chemistry.

Quantum Interfaces to the Nanoscale

Here, we offer our perspective on how defect centers can mediate the transfer of quantum information between many leading qubit platforms.

Defect polaritons from first principles

Precise control over the electronic and optical properties of defect centers in solid-state materials is necessary for their applications as quantum sensors, transducers, memories, and emitters. In this study, we show that the optical properties of defects change drastically when they are placed inside a cavity that concentrates the vacuum electric fields.

Sum-frequency excitation of coherent magnons

Efficiently driving magnons, or quantized spin waves, in magnetic materials is necessary for next-generation memory devices. Here, we show that magnons can be driven with lasers, either directly or indirectly by first driving phonons, or quantized lattice vibrations. This more energy-efficient mechanism may enable magnons to be driven in a wider range of materials.

Spin Emitters beyond the Point Dipole Approximation in Nanomagnonic Cavities

Precise control over the flow of energy in matter, such as light-absorbing molecules in plants that absorb light, transmit it through the backbone of the molecule, and convert it to chemical energy, is crucial. Here, we show that the flow of energy blocked in a single electron spin in a molecule or defect can be unblocked by placing it near a small magnetic nanoaparticle.

Hybridized Defects in Solid-State Materials as Artificial Molecules

Defects in solid-state materials, where a single atom in a crystalline material is replaced by others, are leading candidates for materials underlying scalable quantum computers because they can behave as "artificial atoms" that store and transmit quantum information easily. Here, we show that defects can bond with nearby defects to form "artificial molecules," thereby introducing a powerful way to design defects with the exact properties needed for quantum computation.

Light-matter interaction of a molecule in a dissipative cavity from first principles

Matter placed into environments where the electromagnetic field is strongly concentrated exhibits strange properties that can be leveraged for applications ranging from sunlight collection to chemical synthesis. Here, we develop a method to compute some of these properties from first principles, meaning we use only the chemical structure of the matter and the cavity properties as input.

Nanomagnonic Cavities for Strong Spin-Magnon Coupling and Magnon-Mediated Spin-Spin Interactions

Defects in solid-state materials, where a single atom in a crystalline lattice is replaced with another, may serve as the foundation for scalable quantum computers. While quantum information can be stably stored within the spin of an electron of a single defect, transmitting this information from defect to defect is challenging. Here, we show that small magnetic nanoparticles can help quantum information hop from defect to defect.